Granted, phage therapy typically targets gut pathogens, and in this study the E. gallinarum had traveled to other parts of the body. But many people I have talked to who use phage therapy have reported improved symptoms and in some cases even reversal of autoimmune disease.
And yes, phages that you can buy today without a prescription target Enterococcus bacteria, which includes E. gallinarum.
The gut is a wonderful, mysterious place that most of us neglect.